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Electrocardiographic
Terms modified by Electrocardiographic Selected AbstractsFocal Atrial Tachycardia Originating from the Left Atrial Appendage: Electrocardiographic and Electrophysiologic Characterization and Long-Term Outcomes of Radiofrequency AblationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2007WANG YUN-LONG M.D. Introduction: This study sought to investigate electrophysiologic characteristics and radiofrequency ablation (RFA) in patients with focal atrial tachycardia (AT) arising from the left atrial appendage (LAA). Methods: This study included seven patients undergoing RFA with focal AT. Activation mapping was performed during tachycardia to identify an earlier activation in the left atria and the LAA. The atrial appendage angiography was performed to identify the origin in the LAA before and after RFA. Results: AT occurred spontaneously or was induced by isoproterenol infusion rather than programmed extrastimulation and burst atrial pacing in any patient. The tachycardia demonstrated a characteristic P-wave morphology and endocardial activation pattern. The P wave was highly positive in inferior leads in all patients. Lead V1 showed upright or biphasic (±) component in all patients. Lead V2,V6 showed an isoelectric component in five patients or an upright component with low amplitude (<0.1 mV) in two patients. Earliest endocardial activity occurred at the distal coronary sinus (CS) ahead of P wave in all seven patients. Mean tachycardia cycle length was 381 ± 34 msec and the earliest endocardial activation at the successful RFA site occurred 42.3 ± 9.6 msec before the onset of P wave. RFA was acutely successful in all seven patients. Long-term success was achieved in seven of the seven over a mean follow-up of 24 ± 5 months. Conclusions: The LAA is an uncommon site of origin for focal AT (3%). There were consistent P-wave morphology and endocardial activation associated with this type of AT. The LAA focal ablation is safe and effective. Long-term success was achieved with focal ablation in all patients. [source] Electrocardiographic and Electrophysiologic Characteristics of Midseptal Accessory PathwaysJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2005SHIH-LING CHANG M.D. Background: The purpose of the present study was to investigate the electrocardiographic and electrophysiologic characteristics of right midseptal (RMS) and left midseptal (LMS) accessory pathways (APs), and to develop a stepwise algorithm to differentiate RMS from LMS APs. Methods and Results: From May 1989 to February 2004, 1591 patients with AP-mediated tachyarrhythmia underwent RF catheter ablation in this institution, and 38 (2.4%) patients had MS APs. The delta wave and precordial QRS transition during sinus rhythm, retrograde P wave during orthodromic tachycardia, and electrophysiologic characteristic and catheter ablation in 30 patients with RMS APs and 8 patients with LMS APs were analyzed. There was no significant difference in electrophysiologic characteristics and catheter ablation between RMS and LMS APs. The polarity of retrograde P wave during orthodromic tachycardia also showed no statistical difference between patients with RMS and LMS APs. The delta wave polarity was positive in leads I, aVL, and V3 to V6 in patients with RMS and LMS APs. Patients with LMS APs had a higher incidence of biphasic delta wave in lead V1 than patients with RMS APs (80% vs. 15%, P = 0.012). The distributions of precordial QRS transition were different between RMS APs (leads V2; n = 10, V3; n = 7 and V4; n = 3) and LMS APs (leads V1; n = 1 and V2; n = 4) (P = 0.03). The combination of a delta negative wave in lead V1 or precordial QRS transition in lead V3 or V4 had a sensitivity of 90%, specificity of 80%, positive predictive value of 95%, and negative predictive value of 66% in predicting an RMS AP. Conclusions: Delta wave polarity in lead V1 and precordial QRS transition may differentiate RMS and LMS APs. [source] Short Atrioventricular Mahaim Fibers: Observations on Their Clinical, Electrocardiographic, and Electrophysiologic ProfileJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2005EDUARDO BACK STERNICK M.D. Introduction: A short atrioventricular decrementally conducting accessory pathway is an uncommon variant of preexcitation. Available data from small series suggest that their decremental properties might not be caused by A-V nodal-like tissue. Methods: We compared clinical, electrocardiographic and electrophysiologic parameters in two groups of patients: 8 patients with a short A-V Mahaim pathway (Group A), and 33 patients with atriofascicular pathways (Group B). Radiofrequency catheter ablation was carried out guided by activation mapping at the annulus in Group A patients and targeting the "M" potential in Group B patients. Results: After ablation of all associated rapidly conducting bypass tracts, 7 of the 8 Group A patients showed clear preexcitation. In only 1 of 8 patients the short A-V Mahaim fiber was actively engaged in a reentrant tachycardia circuit. During radiofrequency catheter ablation an automatic rhythm occurred in 4 of 8 patients. Intravenous adenosine caused conduction a block in the Mahaim fiber in 3 of the 5 patients tested. In group B, no patient showed clear preexcitation (P < 00001) while 72% had a minimal preexcitation pattern. Twenty-nine of the 33 patients had a circus movement tachycardia with AV conduction over the atriofascicular fiber. During radiofrequency catheter ablation 30 of 33 patients showed accessory pathway automaticity. Adenosine caused transient block at the atriofascicular pathway in 11 (92%) of the 12 patients tested. Conclusions: While short decrementally conducting right-sided accessory pathways show a typical ECG pattern different from atriofascicular pathways, their electrophysiologic properties do not seem to be uniform. Those pathways can be successfully interrupted by catheter ablation. [source] Predictors of Complete Heart Block After Alcohol Septal Ablation for Hypertrophic Cardiomyopathy and the Timing of Pacemaker ImplantationJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 1 2007F.R.A.C.P., SEIFEDDIN S. EL-JACK M.B.B.S. Catheter-based alcohol septal ablation has recently been introduced for the treatment of left ventricular outflow tract obstruction in hypertrophic obstructive cardiomyopathy. It is associated with various conduction disturbances and may lead to transient or persistent complete heart block (CHB). Electrocardiographic (ECG) changes and predictors of developing CHB and the timing of permanent pacemaker implantation have been variable among the different studies. Among 50 patients studied, we found that a new right bundle branch pattern was the most common new ECG change after septal ablation and that baseline left bundle branch block was strongly associated with the development of CHB (P = 0.004); 9 patients (18%) required permanent pacemaker implantation of whom 7 (78%) remained pacemaker dependent at 14 days with no delayed recovery of atrioventricular conduction. This favors an early pacemaker implantation strategy. [source] Electrocardiographic Activity before Onset of Postoperative Atrial Fibrillation in Cardiac Surgery PatientsPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2008MIRELA OVREIU Ph.D. Background:Electrocardiographic (ECG) characteristics were analyzed in postoperative cardiac surgery patients in an attempt to predict development of new-onset postoperative atrial fibrillation (AF). Methods:Nineteen ECG characteristics were analyzed using computer-based algorithms. The parameters were retrospectively analyzed from ECG signals recorded in postoperative cardiac surgery patients while they were in the cardiovascular intensive care unit (CVICU) at our institution. ECG data from 99 patients (of whom 43 developed postoperative AF) were analyzed. A bootstrap variable selection procedure was applied to select the most important ECG parameters, and a multivariable logistic regression model was developed to classify patients who did and did not develop AF. Results:Premature atrial activity (PAC) was greater in AF patients (P < 0.01). Certain heart rate variability (HRV) and turbulence parameters also differed in patients who did and did not develop AF. In contrast, P-wave morphology was similar in patients with and without AF. Receiver operating curve (ROC) analysis applied to the model produced a C-statistic of 0.904. The model thus correctly classified AF patients with more than a 90% sensitivity and a 70% specificity. Conclusion:Among the 19 ECG parameters analyzed, PAC activity, frequency-domain HRV, and heart rate turbulence parameters were the best discriminators for postoperative AF. [source] Effects of Sex and Age on Electrocardiographic and Cardiac Electrophysiological Properties in AdultsPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2001TARESH TANEJA TANEJA, T., et al.: Effects of Sex, and Age on Electrocardiographic and Cardiac Electrophysiological Properties in Adults. Although differences in patient sex in heart rate and QT interval have been well characterized, sexual differences in other cardiac electrophysiological properties have not been well defined. The study population consisted of 354 consecutive patients without structural heart disease or preexcitation who underwent clinically indicated electrophysiological testing in the drug-free state. Atrial, AV nodal, and ventricular effective refractory periods (AERP, AVNERP, VERP) were determined at a pacing cycle length of 500 ms using an 8-beat drive train and 3-second intertrain pause. There were 124 men and 230 women with a mean age of 45 ± 19 and 47 ± 18 years, respectively The sinus cycle length (SCL) was longer in men than in women (864 ± 186 and 824 ± 172 ms, respectively, P < 0.05). The QRS duration was significantly longer in men (90 ± 12 ms) than women (86 ± 13 ms) (P < 0.005). The HV interval was 48 ± 9 ms in men and 45 ± 8 ms in women (P < 0.05). The sinus node recovery time (SNRT) was significantly longer in men than in women (1215 ± 297 ms and 1135 ± 214 ms, respectively, P < 0.05). AERP and VERP were similar in both sexes. Aging did not influence sexual differences in cardiac electrophysiological properties, although, it independently prolonged the SCL, PR, and QT intervals, AH and HV intervals, SNRT, AVNERP, and the AV Wenckebach cycle length. The SCL, QRS duration, HV interval, and SNRT were significantly longer in men than in women. Aging prolonged cardiac conduction and increased the SCL but the effects were similar in both sexes. AERP and VERP were unaffected by aging or sex. [source] Sequence of Electrocardiographic and Acoustic Cardiographic Changes and Angina during Coronary Occlusion and Reperfusion in Patients Undergoing Percutaneous Coronary InterventionANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2009A.N.P., Eunyoung Lee R.N., Ph.D. Background: Previous studies have suggested that ventricular function may be impaired without or prior to electrocardiographic changes or angina during ischemia. Understanding of temporal sequence of electrical and functional ischemic events may improve the detection of myocardial ischemia. Methods: A prospective study was performed in 21 subjects undergoing percutaneous coronary intervention (PCI) who had both ST amplitude changes >2 standard deviations above baseline on 12-lead electrocardiography (ECG), and new or increased third or fourth heart sound (S3 or S4) intensity measured by computerized acoustic cardiography. The sequence of the onset and resolution of these signs of ischemia were examined following coronary balloon inflation and deflation. Results: Electrocardiographic ST amplitude and diastolic heart sound changes occurred contemporaneously, shortly after coronary occlusion (mean onset from balloon inflation; ST changes, 21 ± 17 seconds; S4, 25 ± 26 seconds; S3, 45 ± 43 seconds). In 40% of patients, a new or increased S3 or S4 developed earlier than ST changes. Anginal symptoms occurred in only 2 of the 21 subjects during ischemia with a mean onset time of 68 seconds. ST-segment changes resolved earliest (33 seconds after balloon deflation) while diastolic heart sounds (89 ± 146 seconds) and angina (586 ± 653 seconds) resolved later. Conclusion: A new or intensified S3 and/or S4 occurred contemporaneously with electrocardiographic changes during ischemia. These diastolic heart sounds persisted longer than ST changes following coronary reperfusion. Acoustic cardiographic assessment of diastolic heart sounds may aid in the early detection of myocardial ischemia, particularly in those patients with an uninterpretable ECG. [source] Differences in sino-atrial and atrio-ventricular function with age and sex attributable to the Scn5a+/, mutation in a murine cardiac modelACTA PHYSIOLOGICA, Issue 1 2010K. Jeevaratnam Abstract Aim:, To investigate the interacting effects of age and sex on electrocardiographic (ECG) features of Scn5a+/, mice modelling Brugada syndrome. Methods:, Recordings were performed on anaesthetized wild-type (WT) and Scn5a+/, mice and differences attributable to these risk factors statistically stratified. Results:,Scn5a+/, exerted sex-dependent effects upon sino-atrial function that only became apparent with age. RR intervals were greater in old male than in old female Scn5a+/,. Atrio-ventricular (AV) conduction was slower in young female mice, whether WT and Scn5a+/,, than the corresponding young male WT and Scn5a+/,. However, PR intervals lengthened with age in male but not in female Scn5a+/, giving the greatest PR intervals in old male Scn5a+/, compared with either old male WT or young male Scn5a+/, mice. In contrast, PR intervals were similar in old female Scn5a+/, and in old female WT. QTc was prolonged in Scn5a+/, compared with WT, and female Scn5a+/, compared with female WT. Age-dependent alterations in durations of ventricular repolarization relative to WT affected male but not female Scn5a+/,. Thus, T-wave durations were greater in old male Scn5a+/, compared with old male WT, but indistinguishable between old female Scn5a+/, and old female WT. Finally, analysis for combined interactions of genotype, age and sex demonstrated no effects on P wave and QRS durations and QTc intervals. Conclusion:, We demonstrate for the first time that age, sex and genotype exert both independent and interacting ECG effects. The latter suggest alterations in cardiac pacemaker function, atrio-ventricular conduction and ventricular repolarization greatest in ageing male Scn5a+/,. [source] Outcomes and Prognostic Factors of Systolic as Compared With Diastolic Heart Failure in Urban AmericaCONGESTIVE HEART FAILURE, Issue 1 2005Peter A. McCullough MD We sought to describe a large heart failure (HF) population with respect to systolic and diastolic abnormalities in terms of demographics, echocardiographic parameters, and survival. Using data abstracted from the Resource Utilization Among Congestive Heart Failure (REACH) study, a targeted subpopulation of 3471 patients had electrocardiographic, echocardiographic, and clinical data taken from automated sources during the first year of diagnosis. Among the HF population, 1811 (52.2%) had diastolic HF. Prevalence of diastolic HF trended with age, from 46.4% in those less than 45 years to 58.7% in those 85 years or older (p=0.001 for trend). Patients with diastolic HF had a higher mean ejection fraction (55.7% vs. 28.0%), lower left ventricular end-systolic diameter (3.11 vs. 4.74 cm), and lower left atrium: aortic outlet ratio (1.28 vs. 1.38) (p=0.001 for each comparison). Annualized age, sex, and race-adjusted mortality were 11.2% and 13.0% for those with diastolic and systolic HF, respectively (p=0.001). In a large, racially mixed, urban HF population, those with diastolic HF predominate and enjoy better-adjusted survival than counterparts with systolic HF. [source] Methods for detecting coronary disease: epidemiology and clinical managementACTA PHYSIOLOGICA, Issue 2 2002O. Faergeman ABSTRACT The epidemic of atherosclerotic disease in wealthy countries had probably begun by 1900. Although a few physicians understood how atherosclerosis/thrombosis of the coronary arteries caused angina pectoris and myocardial infarction, the medical community did not accept that relationship until the 1920s. In wealthy countries, the epidemic peaked in mid-century, and it is now advancing in poor countries and in countries becoming affluent. Two recent developments in methods for disease detection, however, will profoundly affect not only our understanding of the epidemic of atherosclerotic disease, but also our management of patients. A redefinition of the clinical diagnosis of myocardial infarction, a well-used but imperfect measure of the epidemic, was published in September 2000. Criteria employed for about 50 years have now been replaced by criteria based on sensitive biochemical markers of necrosis of as little as 1 g of myocardium, accompanied by chest discomfort or electrocardiographic (ECG) changes, or following coronary artery intervention. The new criteria, adopted by the major societies of cardiology in Europe and the United States, is likely to increase the apparent incidence and prevalence of coronary heart disease (CHD). In the beginning of the twentieth century, diagnosis of CHD required an autopsy. In the end it was carried out by angiography as well, but it could not be applied to large proportions of the population. That has now been changed by new, non-invasive methods of computer tomography (CT) and magnetic resonance imaging (MRI), and patients, however, asymptomatic, will expect treatment for a disease that physicians have detected. Coronary artery disease (CAD) will be to CHD what occult cancer is to cancer. [source] Effect of insulin infusion on electrocardiographic findings following acute myocardial infarction: importance of glycaemic controlDIABETIC MEDICINE, Issue 2 2009R. M. Gan Abstract Aims, To determine the effects of insulin infusion and blood glucose levels during acute myocardial infarction (AMI) on electrocardiographic (ECG) features of myocardial electrical activity. Methods, ECGs at admission and 24 h were examined in a randomized study of insulin infusion vs. routine care for AMI patients with diabetes or hyperglycaemia. Results were analysed according to treatment allocation and also according to average blood glucose level. Results, ECG characteristics were similar at admission in both groups. Patients allocated to conventional treatment had prolongation of the QT interval (QTc) after 24 h but those receiving infused insulin did not. In patients with a mean blood glucose in the first 24 h > 8.0 mmol/l, new ECG conduction abnormalities were significantly more common than in patients with mean blood glucose , 8.0 mmol/l (15.0% vs. 6.0%, P < 0.05). Conclusions, Prevention of QTc prolongation by administration of insulin may reflect a protective effect on metabolic and electrical activity in threatened myocardial tissue. Abnormalities of cardiac electrical conduction may also be influenced by blood glucose. [source] The Impact of Race on the Acute Management of Chest PainACADEMIC EMERGENCY MEDICINE, Issue 11 2003Arvind Venkat MD Abstract Objectives: African Americans with acute coronary syndromes receive cardiac catheterization less frequently than whites. The objective was to determine if such disparities extend to acute evaluation and noninterventional treatment. Methods: Data on adults with chest pain (N= 7,935) presenting to eight emergency departments (EDs) were evaluated from the Internet Tracking Registry of Acute Coronary Syndromes. Groups were selected from final ED diagnosis: 1) acute myocardial infarction (AMI), n= 400; 2) unstable angina/non,ST-elevation myocardial infarction (UA/NSTEMI), n= 1,153; and 3) nonacute coronary syndrome chest pain (non-ACS CP), n= 6,382. American College of Cardiology/American Heart Association guidelines for AMI and UA/NSTEMI were used to evaluate racial disparities with logistic regression models. Odds ratios (ORs) were adjusted for age, gender, guideline publication, and insurance status. Non-ACS CP patients were assessed by comparing electrocardiographic (ECG)/laboratory evaluation, medical treatment, admission rates, and invasive and noninvasive testing for coronary artery disease (CAD). Results: African Americans with UA/NSTEMI received glycoprotein IIb/IIIa receptor inhibitors less often than whites (OR, 0.41; 95% CI = 0.19 to 0.91). African Americans with non-ACS CP underwent ECG/laboratory evaluation, medical treatment, and invasive and noninvasive testing for CAD less often than whites (p < 0.05). Other nonwhites with non-ACS CP were admitted and received invasive testing for CAD less often than whites (p < 0.01). African Americans and other nonwhites with AMI underwent catheterization less frequently than whites (OR, 0.45; 95% CI = 0.29 to 0.71 and OR, 0.40; 95% CI = 0.17 to 0.92, respectively). A similar disparity in catheterization was noted in UA/NSTEMI therapy (OR, 0.53; 95% CI = 0.40 to 0.68 and OR, 0.68; 95% CI = 0.47 to 0.99). Conclusions: Racial disparities in acute chest pain management extend beyond cardiac catheterization. Poor compliance with recommended treatments for ACS may be an explanation. [source] Effects of intravenous lidocaine overdose on cardiac electrical activity and blood pressure in the horseEQUINE VETERINARY JOURNAL, Issue 5 2001G. A. MEYER Summary This study aimed to identify blood serum lidocaine concentrations in the horse which resulted in clinical signs of intoxication, and to document the effects of toxic levels on the cardiovascular and cardiopulmonary systems. Nineteen clinically normal mature horses of mixed breed, age and sex were observed. Lidocaine administration was initiated in each subject with an i.v. loading dose of 1.5 mg/kg bwt and followed by continuous infusion of 0.3 mg/kg bwt/min until clinical signs of intoxication were observed. Intoxication was defined as the development of skeletal muscle tremors. Prior to administration of lidocaine, blood samples for lidocaine analysis, heart rate, mean arterial blood pressure, systolic blood pressure, diastolic blood pressure, respiratory rate and electrocardiographic (ECG) data were collected. After recording baseline data, repeat data were collected at 5 min intervals until signs of intoxication were observed. The range of serum lidocaine concentrations at which the clinical signs of intoxication were observed was 1.85,4.53 ,g/ml (mean ± s.d. 3.24 ± 0.74 ,g/ml). Statistically significant changes in P wave duration, P-R interval, R-R interval and Q-T interval were observed in comparison to control values, as a result of lidocaine administration. These changes in ECG values did not fall outside published normal values and were not clinically significant. Heart rate, blood pressures and respiratory rates were unchanged from control values. This study establishes toxic serum lidocaine levels in the horse, and demonstrates that there were no clinically significant cardiovascular effects with serum lidocaine concentrations less than those required to produce signs of toxicity. [source] Continuous Electrocardiographic Monitoring and Cardiac Arrest Outcomes in 8,932 Telemetry Ward PatientsACADEMIC EMERGENCY MEDICINE, Issue 6 2000Michael J. Schull MD Abstract. Objective: To estimate the benefit of routine electrocardiographic (ECG) telemetry monitoring on in-hospital cardiac arrest survival. Methods: In a tertiary care hospital, all telemetry ward admissions and cardiac arrests occurring over a five-year period were reviewed. Ward location and survival to discharge were determined for all patients outside of critical care areas. Results: During the study period, 8,932 patients were admitted to the telemetry ward, and 20 suffered cardiac arrest (0.2%; 95% CI = 0.1 to 0.3). Telemetry monitors signaled the onset of cardiac arrest in only 56% (95% CI = 30 to 80) of monitored arrests. Three patients survived to discharge, and in two of these three patients the arrest onset was signaled by the monitor. This yields a monitor-signaled survival rate among telemetry ward patients of 0.02% (95% CI = 0 to 0.05). All survivors suffered significant arrhythmias prior to their cardiac arrests. Conclusions: Cardiac arrest is an uncommon event among telemetry ward patients, and monitor-signaled survivors are extremely rare. Routine telemetry offers little cardiac arrest survival benefit to most monitored patients, and a more selective policy for telemetry use might safely avoid ECG monitoring for many patients. [source] Naratriptan in the Prophylaxis of Cluster HeadacheHEADACHE, Issue 1 2002Elizabeth Loder MD A 36-year-old man with cluster headache refractory to trials of standard prophylactic treatment and only partially responsive to parenteral sumatriptan and inhaled oxygen was admitted to an inpatient pain unit. The diagnosis of cluster headache was confirmed by direct observation of a typical attack. Despite efforts at prophylaxis, the patient continued to experience three to four severe headaches per day. Attempts to control his headaches with scheduled parenteral dihydroergotamine were successful, but headaches recurred when the medication was tapered, and continuous or intermittent use of parenteral dihydroergotamine was not felt to be a practical option for the patient. Naratriptan 2.5 mg twice daily completely abolished his headaches, which recurred when the medication was discontinued. No electrocardiographic or laboratory abnormalities were observed during treatment, and the patient reported no side effects. [source] Tako-tsubo-like cardiomyopathy after EpiPen administrationINTERNAL MEDICINE JOURNAL, Issue 11 2008C. M. Zubrinich Abstract Tako-tsubo-like cardiomyopathy is characterized by acute chest pain, electrocardiographic changes and increased cardiac enzymes in the absence of obstructive coronary vessel disease. We describe the development of tako-tsubo-like cardiomyopathy in an elderly woman after the use of an EpiPen for generalized urticaria and angioedema. As adrenaline may participate in the pathogenesis of this condition, the need for careful patient selection and education in the use of adrenaline self-injectors remains imperative. [source] Electrocardiographic Findings, Device Therapies, and Comorbidities in Octogenarian Implantable Defibrillator RecipientsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2010JAMES D. DANIELS M.D. Implantable Defibrillators in Octogenarians.,Background: The use of implantable cardioverter-defibrillators (ICDs) in octogenarians is poorly defined. Objective: To assess baseline electrocardiographic (ECG) findings, arrhythmia episodes, and development of severe nonarrhythmic illness or death in patients aged ,80 years at ICD implantation, and to compare them with younger patients. Methods: Medical records and device interrogations for 199 patients ,70 years old who underwent ICD implantation were reviewed. Patients were divided into 3 groups based on age at the time of implant: age 70,74 (group 1; 88 patients), age 75,79 (group 2; 67 patients), and age ,80 (group 3; 44 patients). Results: ECGs: Octogenarians were more likely to have sinus bradycardia (SB) (P = 0.047) and left bundle branch block (LBBB) (P = 0.043) compared to younger patients. There was no difference among groups in the proportion of patients with atrial fibrillation or any degree of AV block. Therapies: There was no difference between age groups in any therapy (P = 0.78), appropriate therapy (P = 0.54), or inappropriate therapy (P = 0.21) per patient-year. There was no difference between groups in time-to-first therapy of any type (P = 0.71). Nonarrhythmic death/morbidity: There was no difference between groups in time to death or serious illness. Conclusion: Our study is the first to evaluate in detail the therapies received by octogenarians after ICD placement. The higher incidence of SB and LBBB might influence the number of pacing sites in octogenarian patients. Very elderly patients have similar rates of arrhythmic episodes and development of severe comorbidities as septuagenarians, and they should not be denied ICD implantation based solely on age. (J Cardiovasc Electrophysiol, Vol. 21, pp. 236,241, March 2010) [source] Idiopathic Left Ventricular Arrhythmias Originating Adjacent to the Left Aortic Sinus of Valsalva: Electrophysiological Rationale for the Surface ElectrocardiogramJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2010TAKUMI YAMADA M.D. IVT Arising Adjacent to the Left Sinus of Valsalva.Background: Idiopathic ventricular arrhythmias (VAs) may be amenable to catheter ablation within or adjacent to the left sinus of Valsalva (LSOV). However, features that discriminate these sites have not been defined. The purpose of this study was to determine the electrocardiographic and electrophysiological features of VAs originating within or adjacent to the LSOV. Methods and Results: We studied 48 consecutive patients undergoing successful catheter ablation of idiopathic VAs originating from the left coronary cusp (LCC, n = 29), aortomitral continuity (AMC, n = 10) and great cardiac vein or anterior interventricular cardiac vein (Epi, n = 9). A small r wave, or rarely an R wave, was typically observed in lead I during the VAs and pacing in these regions. An S wave in lead V5 or V6 occurred significantly more often during both the VAs and pacing from the AMC than during that from the LCC and Epi (p < 0.05 to 0.0001). For discriminating whether VA origins can be ablated endocardially or epicardially, the maximum deflection index (MDI = the shortest time to the maximum deflection in any precordial lead/QRS duration) was reliable for VAs arising from the AMC (100%), but was less reliable for LCC (73%) and Epi (67%) VAs. In 3 (33%) of the Epi VAs, the site of an excellent pace map was located transmurally opposite to the successful ablation site (LCC = 1 and AMC = 2). Conclusions: The MDI has limited value for discriminating endocardial from epicardial VA origins in sites adjacent to the LSOV probably due to preferential conduction, intramural VA origins or myocardium in contact with the LCC. (J Cardiovasc Electrophysiol, Vol. 21, pp. 170-176, February 2010) [source] Activation Delay and VT Parameters in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy: Toward Improvement of Diagnostic ECG CriteriaJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2008MONIEK G.P.J. COX M.D. Introduction: Desmosomal changes, electrical uncoupling, and surviving myocardial bundles embedded in fibrofatty tissue are hallmarks of activation delay in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Currently, generally accepted task force criteria (TFC) are used for clinical diagnosis. We propose additional criteria based on activation delay and ventricular tachycardia (VT) to improve identification of affected individuals. Methods and Results: Activation delay and VT-related 12-lead electrocardiographic (ECG) criteria were studied, while off drugs, in 42 patients with proven ARVD/C according to TFC, and 27 controls with idiopathic VT from the RV outflow tract. Two of three measured TFC could only be identified in a small minority of ARVD/C patients. Additional ECG criteria proposed in this study included (a) prolonged terminal activation duration, an indicator of activation delay; (b) VT with LBBB morphology and superior axis; and (c) multiple different VT morphologies. These criteria were met in 30 (71%), 28 (67%), and 37 (88%) ARVD/C patients, respectively, and in one control patient (P < 0.001). Electrophysiologic studies contributed importantly to yield different VT morphologies. Pathogenic plakophilin-2 mutations were identified in 25 (60%) of ARVD/C patients and in none of the controls. In ARVD/C patients, parameters measured were not significantly different between mutation carriers and noncarriers, except for negative T waves in V1,3, occurring more frequently in patients with mutation. Conclusions: The proposed additional criteria are specific for ARVD/C and more sensitive than the current TFC. Therefore, adding the newly proposed criteria to current TFC could improve ARVD/C diagnosis, independent of DNA analysis. [source] Electrocardiographic and Electrophysiologic Characteristics of Midseptal Accessory PathwaysJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2005SHIH-LING CHANG M.D. Background: The purpose of the present study was to investigate the electrocardiographic and electrophysiologic characteristics of right midseptal (RMS) and left midseptal (LMS) accessory pathways (APs), and to develop a stepwise algorithm to differentiate RMS from LMS APs. Methods and Results: From May 1989 to February 2004, 1591 patients with AP-mediated tachyarrhythmia underwent RF catheter ablation in this institution, and 38 (2.4%) patients had MS APs. The delta wave and precordial QRS transition during sinus rhythm, retrograde P wave during orthodromic tachycardia, and electrophysiologic characteristic and catheter ablation in 30 patients with RMS APs and 8 patients with LMS APs were analyzed. There was no significant difference in electrophysiologic characteristics and catheter ablation between RMS and LMS APs. The polarity of retrograde P wave during orthodromic tachycardia also showed no statistical difference between patients with RMS and LMS APs. The delta wave polarity was positive in leads I, aVL, and V3 to V6 in patients with RMS and LMS APs. Patients with LMS APs had a higher incidence of biphasic delta wave in lead V1 than patients with RMS APs (80% vs. 15%, P = 0.012). The distributions of precordial QRS transition were different between RMS APs (leads V2; n = 10, V3; n = 7 and V4; n = 3) and LMS APs (leads V1; n = 1 and V2; n = 4) (P = 0.03). The combination of a delta negative wave in lead V1 or precordial QRS transition in lead V3 or V4 had a sensitivity of 90%, specificity of 80%, positive predictive value of 95%, and negative predictive value of 66% in predicting an RMS AP. Conclusions: Delta wave polarity in lead V1 and precordial QRS transition may differentiate RMS and LMS APs. [source] Short Atrioventricular Mahaim Fibers: Observations on Their Clinical, Electrocardiographic, and Electrophysiologic ProfileJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2005EDUARDO BACK STERNICK M.D. Introduction: A short atrioventricular decrementally conducting accessory pathway is an uncommon variant of preexcitation. Available data from small series suggest that their decremental properties might not be caused by A-V nodal-like tissue. Methods: We compared clinical, electrocardiographic and electrophysiologic parameters in two groups of patients: 8 patients with a short A-V Mahaim pathway (Group A), and 33 patients with atriofascicular pathways (Group B). Radiofrequency catheter ablation was carried out guided by activation mapping at the annulus in Group A patients and targeting the "M" potential in Group B patients. Results: After ablation of all associated rapidly conducting bypass tracts, 7 of the 8 Group A patients showed clear preexcitation. In only 1 of 8 patients the short A-V Mahaim fiber was actively engaged in a reentrant tachycardia circuit. During radiofrequency catheter ablation an automatic rhythm occurred in 4 of 8 patients. Intravenous adenosine caused conduction a block in the Mahaim fiber in 3 of the 5 patients tested. In group B, no patient showed clear preexcitation (P < 00001) while 72% had a minimal preexcitation pattern. Twenty-nine of the 33 patients had a circus movement tachycardia with AV conduction over the atriofascicular fiber. During radiofrequency catheter ablation 30 of 33 patients showed accessory pathway automaticity. Adenosine caused transient block at the atriofascicular pathway in 11 (92%) of the 12 patients tested. Conclusions: While short decrementally conducting right-sided accessory pathways show a typical ECG pattern different from atriofascicular pathways, their electrophysiologic properties do not seem to be uniform. Those pathways can be successfully interrupted by catheter ablation. [source] Imbalance of plasma membrane ion leak and pump relationship as a new aetiological basis of certain disease statesJOURNAL OF INTERNAL MEDICINE, Issue 6 2003G. Ronquist Abstract. The basis for life is the ability of the cell to maintain ion gradients across biological membranes. Such gradients are created by specific membrane-bound ion pumps [adenosine triphosphatases (ATPases)]. According to physicochemical rules passive forces equilibrate (dissipate) ion gradients. The cholesterol/phospholipid ratio of the membrane and the degree of saturation of phospholipid fatty acids are important factors for membrane molecular order and herewith a determinant of the degree of non-specific membrane leakiness. Other operative principles, i.e. specific ion channels can be opened and closed according to mechanisms that are specific to the cell. Certain compounds called ionophores can be integrated in the plasma membrane and permit specific inorganic ions to pass. Irrespective of which mechanism ions leak across the plasma membrane the homeostasis may be kept by increasing ion pumping (ATPase activity) in an attempt to restore the physiological ion gradient. The energy source for this work seems to be glycolytically derived ATP formation. Thus an increase in ion pumping is reflected by increased ATP hydrolysis and rate of glycolysis. This can be measured as an accumulation of breakdown products of ATP and end-products of anaerobic glycolysis (lactate). In certain disease entities, the balance between ATP formation and ion pumping may be disordered resulting in a decrease in inter alia (i.a.) cellular energy charge, and an increase in lactate formation and catabolites of adenylates. Cardiac syndrome X is proposed to be due to an excessive leakage of potassium ions, leading to electrocardiographic (ECG) changes, abnormal Tl-scintigraphy of the heart and anginal pain (induced by adenosine). Cocksackie B3 infections, a common agent in myocarditis might also induce an ionophore-like effect. Moreover, Alzheimer's disease is characterized by the formation of extracellular amyloid deposits in the brain of patients. Perturbation of cellular membranes by the amyloid peptide during the development of Alzheimer's disease is one of several mechanisms proposed to account for the toxicity of this peptide on neuronal membranes. We have studied the effects of the peptide and fragments thereof on 45Ca2+ -uptake in human erythrocytes and the energetic consequences. Treatment of erythrocytes with the ,1,40 peptide, results in qualitatively similar nucleotide pattern and decrease of energy charge as the treatment with Ca2+ -ionophore A23187. Finally, in recent studies we have revealed and published in this journal that a rare condition, Tarui's disease or glycogenosis type VII, primarily associated with a defect M-subunit of phosphofructokinase, demonstrates as a cophenomenon an increased leak of Ca2+ into erythrocytes. [source] Cardiovascular magnetic resonance in mild to moderate clozapine-induced myocarditis: Is there a role in the absence of electrocardiographic and echocardiographic abnormalities?JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2010Vignendra Ariyarajah MD Abstract Clozapine is an atypical, neuroleptic medication that can cause myocarditis. While the "gold standard" for diagnosis of myocarditis is perceived to be via myocardial biopsy, cardiovascular magnetic resonance (CMR) has also proven its utility in this respect, primarily through its ability to detect myocardial scar by late-gadolinium enhancement (LGE). Until recently, however, clozapine-induced myocarditis specifically has not been known to be associated with LGE on CMR. In that particular case, LGE was demonstrated in a patient with clozapine-induced myocarditis. However, quite important, that patient also had specific abnormalities on the electrocardiogram (ECG) and echocardiogram that corresponded to the area of LGE demonstrated by CMR. We highlight a case series of three patients with clozapine-induced myocarditis and provide a literature review to discuss and critically appraise the true incremental diagnostic value of CMR in such patients with normal ECG and echocardiography. J. Magn. Reson. Imaging 2010;31:1473,1476. © 2010 Wiley-Liss, Inc. [source] 3D coronary motion tracking in swine models with MR tracking cathetersJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2009Ehud J. Schmidt PhD Abstract Purpose To develop MR-tracked catheters to delineate the three-dimensional motion of coronary arteries at high spatial and temporal resolution. Materials and Methods Catheters with three tracking microcoils were placed into nine swine. During breath-holds, electrocardiographic (ECG)-synchronized 3D motion was measured at varying vessel depths. 3D motion was measured in American Heart Association left anterior descending (LAD) segments 6,7, left circumflex (LCX) segments 11,15, and right coronary artery (RCA) segments 2,3, at 60,115 beats/min heart rates. Similar-length cardiac cycles were averaged. Intercoil cross-correlation identified early systolic phase (ES) and determined segment motion delay. Results Translational and rotational motion, as a function of cardiac phase, is shown, with directionality and amplitude varying along the vessel length. Rotation (peak-to-peak solid-angle RCA ,0.10, LAD ,0.06, LCX ,0.18 radian) occurs primarily during fast translational motion and increases distally. LCX displacement increases with heart rate by 18%. Phantom simulations of motion effects on high-resolution images, using RCA results, show artifacts due to translation and rotation. Conclusion Magnetic resonance imaging (MRI) tracking catheters quantify motion at 20 fps and 1 mm3 resolution at multiple vessel depths, exceeding that available with other techniques. Imaging artifacts due to rotation are demonstrated. Motion-tracking catheters may provide physiological information during interventions and improve imaging spatial resolution. J. Magn. Reson. Imaging 2009;29:86,98. © 2008 Wiley-Liss, Inc. [source] Magnetic resonance and computed tomographic evaluation of congenital heart diseaseJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2004Lawrence M. Boxt MD Abstract Magnetic resonance imaging (MRI) and contrast-enhanced computed tomography (CT) provide noninvasive visualization of morphologic changes in pediatric and adult patients with congenital heart disease, as well as the functional changes caused by the underlying morphologic abnormalities. Clinical experience with MRI is richer than that with fast CT, but CT appears to provide accurate and high-quality imagery for diagnosis. The two modalities may be complementary. That is, intracardiac anatomy is so well depicted by MRI, and CT provides exquisite images of the great vessels. Furthermore, in adult patients, MR and CT are helpful in demonstrating and quantitating physiologic changes superimposed by acquired cardiovascular disease on the underlying congenital malformations. Using MRI, spin echo acquisitions provide the image data for evaluation of morphologic changes, and gradient reversal techniques add functional and flow data to complement morphologic changes. Contrast-enhanced electrocardiographic (ECG)-gated multidetector and electron beam CT examination provide morphologic information and may be used as a data set for off-line functional quantitation. J. Magn. Reson. Imaging 2004;19:827,847. © 2004 Wiley-Liss, Inc. [source] Acute Effects of Low Doses of Red Wine on Cardiac Conduction and Repolarization in Young Healthy SubjectsALCOHOLISM, Issue 12 2009Matteo Cameli Background:, Moderate to high blood concentrations of ethanol have been shown to yield acute changes in cardiac electrophysiological properties, but the effect of low concentrations have never been assessed. The role of concomitant changes in clinical variables or cardiac dimensions is also still unknown. This study aimed at exploring the acute effects of low doses of ethanol, administered as Italian red wine, on conduction, depolarization, and repolarization electrocardiographic (ECG) intervals in a population of healthy subjects. Methods:, Forty healthy young volunteers drank a low quantity of red wine (5 ml/kg), and an equal volume of fruit juice in separate experiments. Heart rate, P-wave duration, PR interval, QRS duration, QT interval, corrected QT interval, QT dispersion, and corrected QT dispersion were assessed at baseline and after 60 minutes from challenge. Results:, Mean blood ethanol concentration after drinking was 0.48 ± 0.06 g/l. Compared to the control challenge, significant changes after red wine intake were observed in P-wave duration (from 101 ± 11 to 108 ± 14 milliseconds, p = 0.0006), PR interval (from 153 ± 15 to 167 ± 17 milliseconds, p < 0.0001), QT interval (from 346 ± 28 to 361 ± 24 milliseconds, p < 0.0001), and corrected QT interval (from 388 ± 24 to 402 ± 30 milliseconds, p = 0.0006). None of these changes showed correlations with modifications in clinical or echocardiographic variables. In multivariate analyses aimed at exploring predictors of ECG changes, none of the variables entered the final models. Conclusions:, Low doses of red wine acutely slow cardiac conduction and prolong repolarization in normal individuals. These changes are poorly predictable. The potential arrhythmogenic impact of these effects is worthy of exploration. [source] N-terminal pro B-type natriuretic peptide and left ventricular diameter independently predict mortality in dogs with mitral valve diseaseJOURNAL OF SMALL ANIMAL PRACTICE, Issue 2 2010W. Moonarmart Objectives: To determine whether natriuretic peptide concentrations would predict all cause mortality in dogs with degenerative mitral valve disease. Methods: One hundred dogs with naturally occurring degenerative mitral valve disease were prospectively recruited for this longitudinal study. Analysis of outcome was undertaken for 73 dogs for which the outcome was known. Dogs underwent physical examination, electrocardiography and echocardiography. Natriuretic peptide concentrations were measured by Enzyme-linked immunosorbent assay. The ability of natriuretic peptide concentrations, clinical, electrocardiographic and echocardiographic data, to predict all cause mortality was determined using univariable and multivariable Cox proportional hazards analyses. Results: Thirty dogs died during the period of follow-up. Two variables were independently predictive of all cause mortality; these were the normalised left ventricular end-diastolic diameter and the N-terminal pro B-type natriuretic peptide concentration. An increase of the left ventricular end-diastolic diameter by 0.1 increased the hazard of all cause mortality by 20% (95% confidence interval: 4 to 37%, P=0.01) and a 100 pmol/l increase in N-terminal pro B-type natriuretic peptide increased the hazard by 7% (95 confidence interval: 2 to 11%, P=0.003). Clinical Significance: N-terminal pro B-type natriuretic peptide concentration and left ventricular end-diastolic diameter are significantly and independently predictive of all cause mortality in dogs with degenerative mitral valve disease. [source] Validation of 2 Techniques for Electrocardiographic Recording in Dogs and CatsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 4 2006Luca Ferasin Background: Standard electrocardiographic (ECG) recording in the dog and cat is commonly performed in right lateral recumbency, by connecting the ECG leads to the skin of the patient via metallic alligator clips. The jaws of the alligator clips are usually filed or flattened to reduce their uncomfortable pressure on the patient's skin. However, filed and flattened alligator clips can occasionally lose their grip to the skin, causing lead detachment during standard ECG recording. Hypothesis: The aim of the study was to validate two novel ECG recording techniques ("gel" and "pads"). Animals: Six-lead standard ECG recording was obtained from 42 dogs and 40 cats using the standard technique, as well as the two novel methods. Methods: Measurements were taken of the amplitude and duration of P waves and QRS complexes, duration of PQ and QT intervals, and mean electrical axis (MEA). In each recording, five representative complexes were measured, and the results were averaged for each parameter. Results: A good quality ECG recording was obtained with all the three different techniques, although a degree of wandering trace was observed in one third of cats with the "pads" technique. Bland-Altman analysis showed good agreement between the ECG values recorded with the two novel techniques and those recorded with the standard traditional technique. Furthermore, the observed differences were not clinically relevant, except for the R wave amplitude recorded with the "pads" method in cats (-0.35 to 0.37 mV). Conclusions and Clinical Importance: In conclusion, this study supports the reliability and clinical validity of the "gel" and "pads" techniques for ECG recording both in the dog and the cat, with some limitations for the "pads" technique in cats. [source] Quiescent-interval single-shot unenhanced magnetic resonance angiography of peripheral vascular disease: Technical considerations and clinical feasibilityMAGNETIC RESONANCE IN MEDICINE, Issue 4 2010Robert R. Edelman Abstract We performed technical optimization followed by a pilot clinical study of quiescent-interval single-shot MR angiography for peripheral vascular disease. Quiescent-interval single-shot MR angiography acquires data using a modified electrocardiographic (ECG)-triggered, fat suppressed, two-dimensional, balanced steady-state, free precession pulse sequence incorporating slice-selective saturation and a quiescent interval for maximal enhancement of inflowing blood. Following optimization at 1.5 T, a pilot study was performed in patients with peripheral vascular disease, using contrast-enhanced MR angiography as the reference standard. The optimized sequence used a quiescent interval of 228 ms, ,/2 catalyzation of the steady-state magnetization, and center-to-out partial Fourier acquisition with parallel acceleration factor of 2. Spatial resolution was 2-3mm along the slice direction and 0.7-1mm in-plane before interpolation. Excluding stented arterial segments, the sensitivity, specificity, and positive and negative predictive values of quiescent-interval single-shot MR angiography for arterial narrowing greater than 50% or occlusion were 92.2%, 94.9%, 83.9%, and 97.7%, respectively. Quiescent-interval single-shot MR angiography provided robust depiction of normal peripheral arterial anatomy and peripheral vascular disease in less than 10 min, without the need to tailor the technique for individual patients. Moreover, the technique provides consistent image quality in the pelvic region despite the presence of respiratory and bowel motion. Magn Reson Med 63:951,958, 2010. © 2010 Wiley-Liss, Inc. [source] Effects of sodium benzoate on the complications of 1.ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 20045% glycine solution using two different intravesical pressures during bladder irrigation Background:, In this experimental study we researched the effects of sodium benzoate on the complications of 1.5% glycine solution using with two different intravesical pressures during bladder irrigation. Methods:, Thirty-six male adult New Zealand rabbits with body weight ranging from 1500 to 2800 g were used in the experiments. The rabbits were randomly allocated to four groups. In groups 1 and 2, 500 ml of 1.5% gylcine was used as irrigating fluid during 30 min, but only group 2 received 500 mg kg,1 of sodium benzoate treatment by oral route immediately after irrigation. In groups 3 and 4, 500 ml of 1.5% glycine was used as irrigating fluid during 60 min, but only group 4 received the same treatment as group 2. Ammonia, urea, sodium, potassium, hemoglobin, hemotocrit and platelet levels were studied at preirrigation and postirrigation on the 4 h and 24 h. Also electrocardiographic (ECG) changes were monitored at the same time with blood parameters. Results:, At 4 h postirrigation, Na+ levels were decreased significantly in group 1 and non-significantly in group 3 when compared with preirrigation levels. But these levels were not changed in groups 2 and 4. Both at 4 h and 24 h, ammonia and urea levels were significantly increased in groups 1 and 3. Ammonia level was decreased but the urea level was not changed in groups 2 and 4 at the same time points. K+ level was significantly changed only in group 1 at 4 h and 24 h. Hemoglobin and hemotocrit concentrations were decreased both at 4 h and 24 h compared with preirrigation levels in all groups. Also there were ECG changes between the treated and untreated groups. Conclusion:, Sodium benzoate was very effective against the complications of 1.5% glycine during bladder irrigation experimentally. But this needs further investigation, especially for the applicability of this new treatment model in human TURP syndrome. [source] | ||||||||||||||||||||||||||||